CASRN: 77-36-1
Drug Levels and Effects
Summary of Use during Lactation
Although amounts of chlorthalidone in milk are not great, its slow clearance may lead to accumulation in the infant, especially while nursing a newborn or preterm infant. It may also suppress lactation. An alternate drug may be preferred.
Drug Levels
Maternal Levels. In 7 women taking 50 mg of oral chlorthalidone daily prior to and after delivery, milk levels 3 days after delivery (collection times unspecified) ranged from 90 to 860 mcg/L. The authors estimated that the infant would receive about 180 mcg daily of chlorthalidone from milk at this maternal dosage.[1] This would amount to about 6% of the maternal weight-adjusted dosage.
Infant Levels. Relevant published information was not found as of the revision date.
Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
Effects on Lactation and Breastmilk
Chlorthalidone has been used successfully to suppress lactation by giving 200 mg orally right after delivery, followed by 100 mg daily for 3 days in conjunction with fluid restriction and breast binding.[2] However, a comparative study found no difference between chlorthalidone 200 mg daily for 7.6 days and placebo in milk leakage and breast engorgement and pain.[3] The added contribution of the diuretic to fluid restriction and breast binding, which are effective in suppressing lactation, has not been studied. There are no data on the effects of diuretics on established, ongoing lactation.
Alternate Drugs to Consider
References
- 1.
- Mulley BA, Parr GD, Pau WK, et al. Placental transfer of chlorthalidone and its elimination in maternal milk. Eur J Clin Pharmacol 1978;13:129-31. [PubMed: 658109]
- 2.
- Reiher KH. Suppression of lactation by stimulation of diuresis. Zentralbl Gynakol 1963;85:188-90. [PubMed: 13973786]
- 3.
- Vercruysse J. Inhibition of lactation. Comparative study of an estro-androgen and of a diuretic. Brux Med 1966;46:1258-66. [PubMed: 6011090]
Substance Identification
Substance Name
Chlorthalidone
CAS Registry Number
77-36-1
Drug Class
Breast Feeding
Lactation
Milk, Human
Antihypertensive Agents
Thiazide Diuretics
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Publication Details
Publication History
Last Revision: November 15, 2024.
Copyright
Attribution Statement: LactMed is a registered trademark of the U.S. Department of Health and Human Services.
Publisher
National Institute of Child Health and Human Development, Bethesda (MD)
NLM Citation
Drugs and Lactation Database (LactMed®) [Internet]. Bethesda (MD): National Institute of Child Health and Human Development; 2006-. Chlorthalidone. [Updated 2024 Nov 15].